Cyclic phenyleneethynylene 3 bearing optically active amide groups was synthesized by the Sonogashira−Hagihara coupling of ʟ-alanine-derived 3,5-dibromobenzamide 1 and 1,3-diethynylbenzene 2. The formation of 3 was confirmed by MALDI−TOF mass spectrometry along with ¹H/¹³C-NMR and IR spectroscopies. A solution of 3 in CHCl₃ turned into gelled state upon standing for 30 min, and the gel returned into fluid state by vibration. The sol−gel transformation was confirmed by dynamic viscoelastic measurement, wherein the storage modulus became larger than loss modulus around the angular frequency at 0.18 rad/s. A membrane of 3 fabricated by spin-coating on a quartz cell exhibited negative Cotton effects at 291 nm and 305 nm assignable to chirally assembled phenyleneethynylene moieties.

We researched the increase in performance of phenolic resins using lignin-based natural materials, a non-fossil resource without a concern of becoming a cause of environmental problems, and without using fossil resources such as oil and coal, for which there are concerns of depletion and which place major burdens on the environment. First, modified (reactive) lignin with imparted reactivity to herbaceous lignin was newly developed. The developed modified lignin was compounded with phenolic resin, and a phenolic resin molding material containing the modified herbaceous lignin, and molded articles thereof were produced. The produced phenolic resin molded articles containing the modified lignin exhibited an improvement in water resistance, which was a drawback of phenolic resin molded articles produced using herbaceous Synopsis (natural) lignin, and it was clear that phenolic resin molded articles also excelling in heat resistance and electrical insulation properties can be obtained. Moreover, it was also demonstrated that the characteristics of the obtained phenolic resin can be varied by changing the blending ratios of the formaldehyde, aniline, and herbaceous lignin used as raw materials to produce the modified lignin.

A novel monobenzoxazine having two propargyl groups in one molecule was synthesized from a dihydroxyaromatic compound as a raw material. In a dynamic viscoelasticity test, the glass transition point (T_g) of this cured resin exceeding 350 ℃. A thermogravimetry test yielded excellent thermal decomposition resistance. The cured resin therefor exhibits excellent physical and chemical properties required by a next generation power device. High levels of chemical and physical heat resistance were confirmed. In addition, this cured product maintained low a coefficient of thermal expansion and high modulus of elasticity over a wide temperature range. The reasons for the excellent properties of the novel benzoxazine having a propargyl group were examined by investigating the reaction behavior using the model substance and analyzing the composition of the pyrolysis gas.

Synthesis and physical properties of C-methylcalix[4]resorcinarene (CRA) derivatives were examined relevant to novel cross-linkers for epoxy thermosetting resin system. The CRA derivatives were synthesized by the reaction of CRA with glycidyl phenyl ether (PGE), acetyl chloride (AC), and allyl bromide, yielding CRA−PGE, CRA−AC, and CRA−AE, respectively. Among them, CRA−AE had better solubility and flowability. Furthermore, the curing material could be obtained by epoxy thermosetting system using CRA−AE, and its no T_g could be shown, i.e., it is a T_g-less cured resin.

In recent years, as electronic devices become higher in performance, higher performance is required for components. Various characteristics are required for the resin used for electronic materials. For example, high heat resistance for lead-free soldering process, flame retardance for environmental regulation, low dielectric properties for high speed transmission, low thermal expansion coefficient for reliability during mounting, low water absorption rate, and so on. Various resins have been developed to meet these requirements. This review introduces development of resin with high heat resistance, low dielectric property and flame retardance.